Process and catalyst for polymerization



United States Patent IO PROCESS AND CATALYST FOR POLYMERIZATION .Telfer L. Thomas, Sarnia, Lambton, Ontario, Canada,

assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Dec. 8, 1958, Ser. No. 778,635

4 Claims. (Cl. 260-68315) This invention relates to improved processes and catalysts for the polymerization of unsaturated carbon compounds. In particular, it relates to the liquid phase I polymerization of C to C olefinic hydrocarbons.

More particularly, it relates to a process and a catalyst for producing good yields of high quality polymer containing to 30 carbon atoms per molecule by contacting C to C olefins with a catalyst containingboron trifluoride and phosphoric acid of about 100 to 150% concentration.

In one embodiment, the invention relates to the further polymerization of lower boiling olefinic polymers,

e.g. dimers and trimers of C to C olefin monomers, to 7 C and 0 olefins boiling above about 390 F.

The large use of synthetic detergents has increased the demand for large quantities of C to C polyolefins boiling in the 390 to 800 F. range for making detergent alkylate. In the past, dodecylene or tetrapropylene has been an accepted raw material for alkylation with benzene and ultimate conversion to alkyl aryl sulfonate .p'ropylene recycle have met with little success since the increase in Q, to C production is too small to make this process economical. The term a typical tetrapropylene process is used herein to refer to the well known U.O.P. polymerization process wherein propylene and propylene-butylene feedstocks are polymerized to C to C 5; olefins by passage over a catalyst of phosphoric acid on kieselguhr at pressures from 200 to 2000 p.s.i. and temperatures above 280 F.

Higher molecular weight olefins, C to C are of value for use in the production of oil-soluble sulfonates and plasticizers, and olefins of both the lower and higher molecular weight are useful as chemical intermediates.

It has now been discovered that a high single run conversion with a high selectivity to C 3 through C olefins can be obtained by a liquid phase polymerization of C through C preferably C through C olefins by intimately contacting the olefinic feed in a reaction zone with 1 to 30 L.V. percent, preferably 5 to 20 L.V. percent, of an acid catalyst containing 3 to 50 L.V. percent, preferably 20 to 40 L.V. percent, of boron trifluoride and 50 to 97 L.V. percent of 100 to 150% phosphoric acid. This highly concentrated phosphoric acid may be made from commercial phosphoric acid and phosphorous pentoxide, or by concentrating commercial phosphoric acid. In one embodiment of this catalyst 50 to 70 L.V. percent of 100 to 150% phosphoric acid is mixed with 30 to 50 L.V. percent of an acid complex prepared by 2,976,338 Patented Mar. 21',

V passing boron trifluoride into to phosphoric acid until about 0.4 to 1.0 moles of boron trifluoride are absorbed per mole of acid.

The reaction may be carried out by dispersing the liquid catalyst in the olefinic feedstock, or the catalyst may be adsorbed on 'a suitable adsorbent such as activated 'carbon' or molecular sieve material. This reaction is conducted, at temperatures in the range of 32 to 212 F, preferably 100 to F., and the time of reaction is between A and 5 hours, depending on the starting material and the desired end product. Single run through total conversions of about 65% are obtainable with this catalyst.

It has further been found that the qualities of the catalysts of this invention can be further enhanced by incorporating therein small amounts of a metal acid fluoride, e.g. 0.05 to 10.0 preferably 0.25 to 2.5 W. percent of potassium acid fluoride based on total catalyst, thus forming a catalyst comprising in combination a major proportion of the aforedescribed boron trifluoridephosphoric acid combination and a minor proportion of 'a metal acid fluoride. By this addition total conversions as high as about 75% can be obtained.

The reaction may be carried out at either atmospheric or superatmospheric pressures, e.g. 0 to 2000 p.s.i.g., however, atmospheric pressure is preferred.

This invention may best be understood by reference to the following examples:

' EXAMPLE I A polyphosphoric acid-boron trifluoride catalyst was prepared by mixing 60 volumes of 110% phosphoric acid with 40 volumes of boron trifluoride-phosphoric acid complex. The 110% phosphoric acid-was prepared by 3 adding P 0 in incremental amounts to 86% phosphoric .acid in. a ratio of about 132 grams of P 0 to 183 ml. of

the acid. The boron trifluoride-phosphoric acid com- .plex was prepared by passing boron trifluoride into 100% phosphoric acid at 25 C. until one mole of gas had been absorbed per mole of 100% phosphoric, acid.-

EXAMPLE n A polyphosphoric acid-boron trifluoride catalyst was. prepared as' in Example I except that 1 W. percent The KHF was added to the solution of Example 1. amount of KHF is based on the total catalyst.

EXAMPLE III Three liters of C olefins produced from a copolymeri- 'zation feedstock of propylene and butylene by a conventional U.O.P. type polymerization using phosphoric acid on kieselguhr was fed into a centrifugal pump type reactor and contacted with 10 L.V. percent of the catalyst of Example I. The reaction was carried out at a tem-' light ends. Conversion to C and 0 polymers was about 66%. Of the C and C polymer produced about 90% was in the C through C range.

EXAMPLE IV The polymer product prepared in Example III was examined by the fluorescent indicator method to determine if the catalyst had caused any deterioration of 0, starting material 97% olefinic material C polymer product 100% olefinic material Light ends 75% olefinic material EXAMPLE V Liquid phase polymerization of C olefins was conducted by employing various catalysts and the results compared with the results obtained in Example III. These results and the conditions under which they were conducted are contained in Table I. The phosphoric acid-boron trifluoride-potassium acid fluoride catalysts shown in Table I were prepared in the same manner as trifiuoride-phosphoric acid admixture containing 3 to 50 liquid volume percent of boron trifiuoride and 50 to 97 liquid volume percent of 100 to about 110 weight percent phosphoric acid, and a minor proportion of a potassium acid fluoride.

2. A catalyst in conformance with claim 1 wherein said minor proportion constitutes 0.05 to 10 weight percent of said catalyst.

3. A catalyst in conformance with claim 2 wherein said minor proportion constitutes 0.25 to 2.5 weight percent of said catalyst.

4. An improved process for polymerizing C to C olefins which comprises intimately contacting said olefins in a reaction zone with 1 to liquid volume percent of the catalyst of Example II except for differing the amount 15 an acid catalyst which comprises in combination a major of KHF as recited in the table. proportion of a boron trifiuoride-phosphoric acid admlx' Table I Total Products, Percent Selectivity Percent Percent Olefin Average Reaction O1z+and Owl-and Catalyst Feed Temp., Time, C11 Con- 013C011- Percent Percent Percent Percent F. Hr. version version light ends CIR-C15 01 -0 015+ (i-390 (390460 (MiG-480 (4s0+ F.) F.) F.) F.)

3:2::86% 1131 04; BFs-HsPO: C1 130 1% 40 36.8 63.2 33.1 8:2:1110%H3PO;; 98% H2304 O1 130 1% 53 47.7 52.3 40.5 3.2 as 8:2::11()% HQPOi; 98% H2SO4+1% oUsol O1 130 1 /2 55 50. 0 50. 0 42. 6 2. 2 5. o 3;2==100% HzPOt BFs-HePO; 01 130 1% 56.5 43.5 50.4 0.9 4.8 322::ll0% H3PO4 BFs-HsPO; With 31, Wt. percent KHF: C1 130 1% 68 64.1 35. 9 55. 5 3:21:11094, H3PO4 BFa-HaPOt with 1% Wt. percent Kurt C1 130 1 /2 75. 9 70.0 30.0 57. 7 4. o s. o

The boron-trifluoride-phosphoric acid complex is too ture containing 3 to 50 liquid volume percent of boron highly reactive to be a suitable polymerization catalyst 35 trifluoride and 50 to 97 liquid volume percent of 100 to when used alone since the rapid evolution of heat reabout weight percent phosphoric acid, and a minor sulting tends to cause deterioration of the polymer proportion of a potassium acid fluoride, at a temperature product. in the range of 32 to 212 F. and a pressure in the Phosphoric acid alone does not effect polymerization range of 0 to 2000 p.s.i.g. for a period of time in the at normal temperatures and pressures. 40 range of M; to 5 hours.

The term L.V. percent as used herein shall be understogd to mean liquid volume percent; References Clted In the file Of this patent The term W. percent as used herein shall be under- UNITED STATES PATENTS stood to mean weight percent.

All percentages recited herein unless otherwise desig- 45 2,416,106 Linn et al. Feb. 18, 1947 nated shall be understood to refer to weight percents. 2,721,889 Murphree et a1. Oct. 25, 1955 What is claimed is: 2,810,77 Sernink Oct. 22, 1957 1. An improved polymerization catalyst which com- 2,814,655 Langlois et al Nov. 26, 1957 prises in combination a major proportion of a boron 2,816,944 Muessig et a1 Dec. 17, 1957 

4. AN IMPROVED PROCESS FOR POLYMERIZING C5 TO C15 OLEFINS WHICH COMPRISES INTIMATELY CONTACTING SAID OLEFINS IN A REACTION ZONE WITH 1 TO 30 LIQUID VOLUME PERCENT OF AN ACID CATALYST WHICH COMPRISES IN COMBINATION A MAJOR PROPORTION OF A BORON TRIFLUORIDE-PHOSPHORIC ACID ADMIXTURE CONTAINING 3 TO 50 LIQUID VOLUME PERCENT OF BORON TRIFLUORIDE AND 50 TO 97 LIQUID VOLUME PERCENT OF 100 TO ABOUT 110 WEIGHT PERCENT PHOSPHORIC ACID, AND A MINOR PROPORTION OF A POTASSIUM ACID FLUORIDE, AT A TEMPERATURE IN THE RANGE OF 32* TO 212*F. AND A PRESSURE IN THE RANGE OF 0 TO 2000 P.S.I.G. FOR A PERIOD OF TIME IN THE RANGE OF 1/8 TO 5 HOURS. 